Quite a weird card, You can mildly overclock a 1070 to be within sniffing distance of a 1080, Within 5FPS of a stock 1080 on The Witcher 3, 5FPS on Fallout 4 and 10FPS in Battlefield 1.
Marketing bumf aside, I reckon this is a pipe cleaner product, Lots of faulty dies left that didn't quite make it to being a 1080, Sell them as 1070 Ti's.
It's true, I just read it on a german news site. Thing is: Asus, EVGA and the likes are not allowed to OC the cards themselves, but they are allowed to deliver OC-profiles via software.
Still very weird, indeed.
from what I am hearing Nvidia has prevented AIBs from selling cards with factory overclocks, though vendors have worked around this by using tools like ASUS GPU Tweak to apply their "advertised overclocks" using a non-bios OC mode.